Polymerization Of Diacetylenes Research Articles

Polymerization of crystalline diacetylenes in the micropores of a polymer matrix

The polymerization of diacetylenes crystallized in the micropores of a stretched out polypropylene matrix is observed and studied. It is established that polymerization of the crystals obtained takes place without an induction period, while the reaction rate is much higher than that for the polymerization of conventional crystals, formed on crystallization of the monomer in the free state. It follows from the data obtained that the kinetic effects are not associated with orientation of the crystals in the matrix and are not due to the action of compressive forces from the matrix side of the crystals introduced. It is suggested that the effects are due to an increase in the rate of polymerization initiation in the polypropylene microcrystals.

Synthesis and polymerization of polar nonsymmetric diacetylenes

Synthesis and polymerization of polar nonsymmetric diacetylenes

Influence of cross-linking on the hysteresis behavior of poly(urethane-diacetylene) segmented copolymers

The influence of diacetylene polymerization within the hard domains on the hysteresis behavior of segmented copolymers with different hard-segment-structures and different levels of phase separation and hard-domain ordering is studied. For elastomers with weakly associated hard segments, it is found that low levels of crosslinking signifcantly reduce the amount of hysteresis that they exhibit at low strains. For elastomers with crystalline hard domains and highly interlocked microstructures, crosslinking increases the level of hysteresis regardless of the level of crosslinking

Solid state polymerization of diacetylenes

Solid state polymerization of diacetylenes

Solid State polymerization of diacetylenes 3.* Crystal and molecular structure of 1,4-bis( 1 -oxyl-2,2,6,6-tetramethyl-4-hydroxy-piperidine- 4-yl)butadiyne

Solid State polymerization of diacetylenes 3.* Crystal and molecular structure of 1,4-bis( 1 -oxyl-2,2,6,6-tetramethyl-4-hydroxy-piperidine- 4-yl)butadiyne

Solid state polymerization of diacetylenes

An X-ray structural study (R = 0.040 for 1871 reflections) of the title compound has been carried out. Molecules in crystal are pseudocentrosymmetric, the piperidine cycle is in a chair conformation. The N atoms of both paramagnetic centers exhibit, in fact, the same degree of pyramidalization, their displacements from the planes of their bonded atoms being 0.111 and 0.119(2) Å. In crystal the molecules form two sets of infinite ribbons (along the [112] and [[unk]12] directions), which are linked with each other via the O – H … O hydrogen bonds along the [001] direction. Although the packing of diacetylene rod-like groups does not correspond to the conditions of topochemical polymerization of diacetylenes, compound I polymerizes in crystal.

Solid state polymerization of diacetylenes

An X-ray structural study of 1,8-bismethacryloyloxyoctadiyne-3,5 ( I ) ( R = 0.051 for 967 reflections) has been carried out. Infinite ribbons of molecules related by the b = 4.5340(4) Å translation can be distinguished in the crystal. The relative orientation of molecules does not permit their topochemical interaction via either shearing mechanism in ribbons involving the triple bonds or four-center polymerization involving the terminal double bonds.

Solid state polymerization of diacetylenes

An X-ray structural study (R = 0.043 for 2704 reflections) of C24H30N2O4 was carried out. The molecule has a skewed conformation, the piperidine cycles are in a chair conformation. The N atoms of paramagnetic groups exhibit different degrees of pyramidalization, due to crystal packing effects, their displacements from the planes of three bonded atoms being 0.111 and 0.042(2) Å. The H-bonds of the O – H … O type link the molecules into layers parallel to the ac-plane. The molecules do not form characteristic stacking necessary for the topochemical solid state polymerization. This fact is in good agreement with the observed inertness of the crystals with respect to the solid state polymerization.

Solid‐state polymerization of diacetylenes under the action of outside forces on crystalline monomer lattice

AbstractThe polymerization of crystalline diacetylenes TS and DCH with different lattice structure was studied under high hydrostatic pressures (up to 4 kbar). It was shown that pressure increases the deformation of chain growing in monomer crystal. The features of such deformation depend on lattice structure that governs the influence of pressure on polymerization rate. We studied also polymerization of diacetylene HD crystals obtained in the pores of stretched polymer (PP). The field of polymer matrix influences the crystal state and the rate of polymerization. It was shown that the interaction of monomer crystals with the matrix leads to growth of more strained chains in these crystals.

Some features of the solid‐state polymerization of diacetylenes

AbstractSimple models of the initial polymerization stage and the polymerization kinetics are considered on the example of the solid state topochemical polymerization of diacetylenes. These models take into account the reaction specifity of the solid state process and the nonlinear character of the monomer units interactions.

Effect of the structure of diacetylene monomers on reactivity in topochemical reactions

The thermal and UV initiated polymerization of diacetylenes of general formula R i CH 2 C≡C C≡C CH 2 R j are studied by a kinetic method. Differences are observed in the order of reaction with respect to the monomer. The data are interpreted from the point of view of the ratio of the polymer chain initiation and propagation constants, and the stability of the biradical intermediate particles. Multi-layer films are obtained by the Langmuir-Schaefer method. It is concluded that at the initiation stage the intermediate particles have an important effect on the monomer to polymer conversion.

Topochemistry of the solid-state polymerization of diacetylenes containing unsaturated side groups

The electronic spectra of polymers in the monomer matrix have been investigated for two structurally similar diacetylenes one of which has side substituents containing the allyl bond which is responsible for degradative chain transfer in the case of liquid-phase polymerization. Melting points and phase transition temperatures were determined for the monomers and polymers by the DSC method. A study of the integral absorption of the polymers in the visible portion of the spectrum shows that the photopolymerization rate for the diacetylene containing the allyl double bond is only one-third of that for the diacetylene that is without the allyl bond. This fact is attributed to a high degree of topotacticity of the solid-state polymerization of crystalline diacetylenes.

Synthesis and Solid-State Polymerization of Novel Diacetylenes for Nonlinear Optics

Abstract Novel unsymmetrical diacetylenes having a carbazolyl group directly bound to acetylene moiety, i.e. 1-(N-carbazolyl)-penta-1,3-diyne-5-ol(CPDO) and the derivatives were synthesized. These diacetylenes can be topochemically polymerized in the solid state and the absorption edges of the polymers are expanded to near infrared, suggesting that π-conjugation of the main chain becomes longer by the electrons donated from carbazolyl groups. From the action spectrum of photocurrent, the band gap energy of poly-CPDO was evaluated to be 1.6 eV, which is smaller than those of so-far-known polydiacetylenes. The ionization potential was estimated to be 4.4 eV.

Membrane-spanning symmetric and asymmetric diyne amphiphiles

Symmetric membrane-spanning diyne amphiphiles of different molecular designs, e.g. single-chain and identical or mixed double-chain compounds, have been synthesized, starting from 10,12-docosadiyne-1,22-diol (1) and 10,12-docosadiynylenedihydrogendimaleate (2), respectively. Esterification of 2 and/or addition of functional thiols at the maleic acid double bond yield symmetric α,ω-dipolar diyne amphiphiles which show structural resemblance to lipids found in the biomembranes of archaebacteria. Asymmetric membrane-spanning diyne amphiphiles are obtained by a straightforward route from 22-hydroxy-10,12-docosadiynoic acid (12) by acylation with functional aromatic dicarboxylic acid anhydrides. Vesicles are formed from a number of symmetric and asymmetric diyne lipid analogues on dispersion in aqueous media, as shown by light- and freeze-fracture electron microscopy and dye entrapment experiments. Stabilization of lecithin liposome membranes towards temperature-induced dye release is effected by incorporation of a macrocyclic membrane-spanning diyne amphiphile. Ultraviolet irradiation of dispersions from asymmetric diynes yields blue and red solutions, indicating that topotactical diacetylene polymerization takes place in these lipid assemblies.

The solid state polymerization of diacetylenes

The solid state polymerization of diacetylenes

The Polymerization of Diacetylenes on Solid Surfaces

AbstractThe influence of solid surfaces on the polymerization of diacetylenes has been studied using 3,5‐octadiyn‐1,8‐diol as a model compound. The first molecular layers on polar surfaces are adsorbed by hydrogen bonds. Their relative orientation hinders the polymerization of these molecules. Subsequent layers can be polymerized by UV radiation. After the unreacted monomer has been extracted a highly stable polymer film remains on the surface.

Calculations on the mechanism of diacetylene polymerization in crystals

Abstract In order to reveal the reasons underlying the peculiarities of solid-state polymerization of diacetylenes theoretical studies of the simplest polymerab

The solid state polymerization of diacetylenes

An X-ray study of 2,4-hexadiyne-1,6-di(p – n-hexyloxy)benzoate was carried out (R = 0.060 for 3223 reflections). The molecule has a skew conformation with the pseudotorsion angle relative to the linear diacetylene moiety equal to −110.0(9)°. The non-ability to polymerization in solid state of the studied diacetylene is explained on the basis of crystal chemistry criteria. Cell parameters of two nearest homologues of the studied compound are determined (for one of them on a polymeric state).

Solid state polymerization of diacetylenes

Solid state polymerization of diacetylenes

Synthesis and characterization of a conducting polyfunctional polydiacetylene

The dimer of 1,11-dodecadiyne was synthesized by controlling the kinetics of the Glaser coupling reaction. Preliminary characterization was accomplished using gel permeation chromatography and differential scanning calorimetry. Microscopic single crystals of the dimer, obtained from a hexane solution, were used for diacetylene polymerization by Co 60 γ-irradiation. The corresponding phase transition from dimer to polymerized dimer was studied by electron diffraction. The existence of an intermediate structure over a range of conversion was apparent from these studies. Macroscopic polymerized single crystals were obtained by γ-ray polymerization X-ray structure analysis was accomplished using these crystals. The unit cell was monoclinic, space group P2/ n. Nine hundred and twenty six observed data points were used for the refinement. The final residual was 0.08. The refined structure was found to be composed of parallel sheets containing alternating trans polyacetylene and polydiacetylene chains. Conductivity (10 −2 ω −1 cm −1 at room temperature) was measured as a function of temperature and the resulting activation energy was compared to the band gap calculated by assuming π electron overlap between polyacetylene and polydiacetylene chains.